Improvements to benchmark tests (AcademySoftwareFoundation#2030)

- Update shaderGenPerformanceTest to use improved MaterialX API workflows.
- Add a readme update to cover Benchmark tests.

source/MaterialXTest/MaterialXGenShader/GenShaderUtil.cpp

@@ -316,8 +316,7 @@ void testUniqueNames(mx::GenContext& context, const std::string& stage)
 void shaderGenPerformanceTest(mx::GenContext& context)
 {
     mx::DocumentPtr nodeLibrary = mx::createDocument();
-    mx::FilePath currentPath = mx::FilePath::getCurrentPath();
-    const mx::FileSearchPath libSearchPath(currentPath);
+    const mx::FileSearchPath libSearchPath(mx::getDefaultDataSearchPath());
 
     // Load the standard libraries.
     loadLibraries({ "libraries" }, libSearchPath, nodeLibrary);
@@ -351,8 +350,9 @@ void shaderGenPerformanceTest(mx::GenContext& context)
     }
 
     // Read mtlx documents
+    mx::FileSearchPath searchPath = mx::getDefaultDataSearchPath();
     mx::FilePathVec testRootPaths;
-    testRootPaths.push_back("resources/Materials/Examples/StandardSurface");
+    testRootPaths.push_back(searchPath.find("resources/Materials/Examples/StandardSurface"));
 
     std::vector<mx::DocumentPtr> loadedDocuments;
     mx::StringVec documentsPaths;
@@ -367,7 +367,7 @@ void shaderGenPerformanceTest(mx::GenContext& context)
     REQUIRE(loadedDocuments.size() > 0);
     REQUIRE(loadedDocuments.size() == documentsPaths.size());
 
-    // Shuffle the order of documents and perform document library import validatation and shadergen
+    // Shuffle the order of documents and perform document library import validation and shadergen
     std::mt19937 rng(0);
     std::shuffle(loadedDocuments.begin(), loadedDocuments.end(), rng);
     for (const auto& doc : loadedDocuments)

source/MaterialXTest/README.md

@@ -82,3 +82,13 @@ When rendering tests are enabled through the `MATERIALX_TEST_RENDER` option, the
 #### HTML Render Comparisons
 - A `tests_to_html` Python script is provided in the [`python/MaterialXTest`](../../python/MaterialXTest) folder, which can be run to generate an HTML file comparing the rendered results in each shading language.
 - Example render comparisons may be found in [commits to the MaterialX repository](https://github.com/AcademySoftwareFoundation/MaterialX/pull/1164), and we encourage developers to post their own results when making changes that have the potential to impact generated shaders.
+
+#### Benchmark Tests
+
+Processing MaterialX documents and generating shaders is an integral part of many pipelines. MaterialX benchmark testing using [Catch2 benchmark framework](https://github.com/catchorg/Catch2/blob/devel/docs/benchmarks.md) and can be enabled using `MATERIALX_BUILD_BENCHMARK_TESTS` CMake macro.
+
+Here is an example of how to run the benchmark test
+
+ `MaterialXTest.exe "GenShader: GLSL Performance Test" --benchmark-samples 10` 
+
+This will iterate and gather 10 samples of the test case and report low, mean and high timing results.